to tell u the honest truth, i don't think it will.
If u look at Roush side exhaust equipped car, and Borla side exhaust equipped car, u can see that Borla tip sit about 1"~1.5" towrds front of the car. So i think it would interfear with side skirts. And i can't see how Roush tip would work with Borla exhaust as Borla tip is about 4" longer then roush tip. if u make custome extention, then i guess it would work.
I think if the cost of Roush side exhaust is concern(and should be, because they are just too damn expensive for what they are), then i think u can get Spintech muffler part# 333SCS, which is direct replacement muffler for Roush side exhaust kits, and have someone bend u a L shaped pipe. that would be most economical way to do it tho. But then u still have to get Roush tips, which is made of Platinam(well, its actually made of cast aluminum, but sure priced like its made of platinam tho)